2025-2026 Audi Radiator Fan Fault P1A7B00 TSB

Audi has issued Technical Service Bulletin (TSB) 2081427/1 to address specific thermal management system concerns in certain 2025-2026 Audi A5, S5, Q5, SQ5, and 2026 Audi A6 models. Owners may experience a check engine light or unusual radiator fan operation related to an incorrect component installation error.

This TSB provides a clear solution for the Audi radiator fan P1A7B00 fault, ensuring proper vehicle operation and preventing potential overheating or cooling system inefficiencies.

Symptoms Owners May Notice

Owners of affected Audi vehicles might observe one or both of the following conditions:

• "Check engine light (MIL) on"
• "Unusual behavior of radiator fan - long run-on or runs at full load"

These symptoms indicate a potential issue within the vehicle's thermal management system, specifically related to the radiator fan's control.

Fault Codes / DTCs

During a diagnostic scan, technicians will find a specific event memory entry logged in the thermal management control unit 00C5. The relevant diagnostic trouble code (DTC) is:

Code	Description	Module
P1A7B00	Control module 1 for radiator fan, incorrect component installed	Thermal management 00C5

This P1A7B00 code points directly to a configuration issue with the radiator fan's control module.

Diagnosis and Trigger Conditions

The primary trigger for this Technical Service Bulletin (TSB) 2081427/1 is the presence of the P1A7B00 fault code in the thermal management control unit 00C5. This code indicates that the system detects an "incorrect component installed" for control module 1 of the radiator fan. Audi notes that the technical background for this specific issue is "Under analysis," meaning the root cause is still being investigated. However, a clear service procedure has been established to address the symptom.

Repair Procedure Summary

To resolve the Audi radiator fan P1A7B00 issue, technicians are instructed to perform a configuration of the HCP4 (J519/onboard supply control unit). This procedure typically involves connecting the vehicle to Audi's diagnostic system and utilizing "Guided Functions" (GFF) to re-calibrate or re-initialize the onboard supply control unit. This ensures that the control module 1 for the radiator fan is correctly recognized and configured by the vehicle's thermal management system, thereby eliminating the "incorrect component installed" error. This is a software-based solution rather than a physical component replacement.

Warranty Coverage Details

Audi outlines specific details for warranty claims related to this TSB 2081427/1:

• Service Number: 9710
• Damage Code: 0040
• Labor Operations: GFF / Guided Functions (0150 0010) and GFF / Guided Functions (0150 0060) for time stated on the diagnostic protocol.

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

Important Note for Out-of-Warranty Vehicles

Owners should be aware that if their vehicle is outside of any applicable warranty, this Technical Service Bulletin is "informational only." This means that while the TSB identifies the problem and its solution, the cost of the repair may not be covered by Audi, and owners might be responsible for diagnostic and repair charges. It is always recommended to discuss warranty coverage with an authorized Audi dealership.

NHTSA ID: 2081427/1